There is a new tool for members to use, a fully functional Scientific Calculator. It will pop-up when you hit any of two links. One in the "Member Quick Links" Drop Down Menu on the Navbar (under "Miscellaneous"), and in the "Member Tools" Drop Down Menu in the Post View. After the Calculator Screen pops up, you can move it around the window, or if you flip to another page, just maximize it again.
See the Screen Shots below: